Reciprocating piston type fluid motor



July 29, 1952 E. E. slvAczEK 2,604,879

RECIPROCATING PISTON TYPE FLUID MOTOR Filed Aug. 13, -1945 t 4 Sheets-Sheet l #M4-L27@ y@ July 29, 1952 E. E. slvAcEK RECIPROCATING PIsToN TYPE FLUID MOTOR 4 Sheets-Sheet 2 Filed Aug. 13, 1945 INVENTOR. E772] ,Z'zQ/qce,

BY Q i V-Me July 29, 1952 E. E. slvAcEK RECIPROCATING PIsToN TYPE FLUID MOTOR 4 Sheets-Sheet 3 Filed Aug. 15. 1945 INVENTOR. -E-f/Z Z ZTI/dce BY July 29, 1952 E. E. slvAcEK 2,504,879

RECIPROCATING PIsToN TYPE FLUID MOTOR Filed Aug. 13, 1945 4 Sheets-Sheet 4 "5" INVENTOR.

' /25 /zg/ of (124 /18 fran/vers.

Patented July 29, 1952 nECIPRocAT-ING s'roNI TYPE. FLUID o i MOTR v Emil Ef SivacekQAnnArbor, Mich., assignor to King-Seeley Corporation, Ann` 1rbor, Mich., a

' corporation of Michigan 1 'Application August .13, 1945, sensi No. 610,551.

The present invention relates to liuid motor mechanisms, and particularly, is directed to the provision of fluid motor mechanisms embodying improved control means for automatically bringing the motors to rest at terminal positions which may be at 'or' beyond the normal limits of travel of the motors.' The fluid `motor mechanisms, while not limited thereto in their application.

have a particular utility in connection with'automotive windshield wiper systems.

Principal objects of the present invention are to ,provide iluid motor mechanisms of the above generally indicated type, which are simplein arrangement, economical of manufacture and assembly and which are reliableand veiiicient'in operation; to provide such constructions ofthe reciprocating type, employing automatically' op- `v erated reversing valve mechanism, and further employing selectively operable parking 'valve mechanisms which, upon .being operated to parking position, establish Huid circuits which cause the motor to automatically move to and come to rest at a terminal position; .to provide such constructions in whichthe parking valve modifies the circuits established, by the reversing valve mechanism, between the motor and the source of power, in such'away as to cause the above move-4 ment to terminal position? and to generally im-y prove the construction and operation of fluid m'otor mechanisms of the above'generallyv indicated type. f

With the above as well :als other and morede-A tailed objects in view, which appear in the 'following description andin the appended claimfa preferred but illustrative embodimentof `the in'- vention is shown inthe' accompanying drawings; throughout the several views of which corremotor embodying the invention;

sponding referencecharacters Aare used todes- Figure 2 is a view in transverse section, taken" along the line 2-2 of Figure 3`;

along the line 3-3 of Figure 1;

Figure 3 is a view'in transverse section, taken'y i -1'Claim; (01.1 21-164) broader aspects, the improvements thereof may Figure 4 is an exploded viewof the reversing valve seat and the reversing valve element;

Figure 5'is'an exploded view Vof the "control valve seat and the control valve element;

Figure 6 is an exploded view in prspetve f..

the reversing and control valve elements; and

Figure '7 is a diagrammatic view, illustrativebf" the various running andparking circuits of the present motor mechanism.

It will be appreciated from va complete understanding ofthe present invention, that, intheii'f be embodied in fluid motor mechanisms of widely differing types and sizes and designed for widely diifering applications. In an illustrative'but not in a limiting sense, the present improvements are herein disclosed. as being embodied in a nuid motor of the double 'piston type, an lexample of which is disclosed and claimed in Patent No.

2,354,189, grantedJuly 2,5, 1944, to I Rupert B. Bell. By way of example, such motorsare well adaptedl for use in yautomotive windshield wiper systems; Referring to the drawings, l the improved motor ID comprises generally a cylindrical housingor cylinder I2 which'is provided with removable end closures' I4. Cylinder I2 slidably receives a piston assembly, comprising a pair of spaced pistons I6, which are rigidly secured, as by studs 'I8, to a connecting rackm).4 The output shaft 2270i the motor, which is rotatably journaled in bearings 24: and 26 provided therefore intheA cylinder I2, has xed thereon, as by a pin 21, a gear segment 28 which'continuously meshes with 'the rackV 20. Accordingly, reciprocating `movements ofthe piston assembly are translated into oscillatory or rocking movements ofthe shaft'22. In'the illustratedjembodiment, shaft 22 is provided with a crank 34, which adapts it forconnection toy the mechanism to be operated by the motor. 'Itwill be appreciated that the piston movements areeifected by applying differential pressures in the chamber spaces Il and I9 between the pistons IfB and the corresponding end Iclosures I4, thespace between pistons I6 being continuously vented to'atmosphere in theillustratd instances;

These differential pressures may, of course, be obtainedfrom any suitable source. For example,

in utilizing the'present motor to drive a wind,-

shield'wiper system, the pressure diil'erential may be` the differenceV between atmospheric pressure and a subatmospheric pressure obtained in usual fashion byA connecting the motor inlet '40V to the intake manifold of the Yassociated engine. I

' 1n' accordance with' the'present invention, mo-

tor I D is providedwith a pair ol?` valve mechanisms'r which, respectively, control the normalv reciprocating movements thereof andthe stopping or parking Aaction`thereof; One offthese valve' mechanisms is of the automatically/operated type, which responds to thearrivalfof the piston as'seinblyatV its normal limits, and reverses! valve mechanism which cause the motor to moya to and come to rest at a terminal position which may be at any desired distance beyond a predetermined one of the normal limits.

Generically, any of a variety of automatic reversing valve mechanisms may be utilized. The illustrated valve ,mechanisms embody the invention of the aforesaidPatent No. 2,354389.v More particularly, the present reversing valve mechanism comprises a valve seat 50, which is located at one face of a valve block 5 I, and which is provided with a series of ve arcuately distributed ports 52, 53, 54, 55, and 56. having a single blind cavity o-r pocket 60- is disposed for movement between thetwo positions,`

shown in the upper two diagrammatic views of A hood valve 58, v -Y posed to be engaged and moved by abutments |02 carried by the rack 20. These abutments |02 may have leaf springs |03 associated therewith to give resilient characteristics to the initial engagement between these abutments and thecarrier 94. It will be appreciated that as the ApistonA assembly moves to the left, viewed in Figure 2, the right-hand piston carried abutment |02 ultimately engages the right-hand arm |00 of the spring carrier 94, initiating a swing- Ving'- movement thereof which ultimately carries vthe lower end of the spring 92 past the overcenter position. .Such carrier movement also causesrthe11.pperand laterally turned end |05 Figure 7. In the upper one of these views, the

trol valve, seat. 66..1l?ort. 52Y .similarly communidates, .by 4way of .a .through passagel, with a port.'|0 lwhichopensthrou'gh the, face of the control. valve. .seat 66. The. center-orV suction port 5,4 continuously.` communicates, through, interconnecting, passages J 2l and 14, with the previously mentioned suctionlline 40. v

R'eversingvalveport 53 continuously .communidates', Aby wayofa, throughpassage '15, with a port. I5 whichopen's. through the. control valve seat; Passage 'I5-isl intersected bya rvertical passage.f .1'1., which.. continuously communicates,.

through. alshortj lateralpassage .18, with alongitudinallvextending passage'l, whichpommuni- Cates .wi`th, the right-l-iand` piston, chamber ISL as ViewedV infligure` 2. Y- Similarly, the. previously mentioned. 'throught passage. 62 is intersected by a vertical .passage l. 8| which, continuously .communicates, through a shortlateral passage 83, with a longitudinally extending ,passage 85, which opens-into the. left-hand piston chamber I3, as v i'eWed'in Figure 2..

The remaining. reversingvalve port 55 continuously communicates, by way .offa .throughpassage 81, with a pocket 89 provided inthaace 66 ofthe control valve. v

Comingnow tofthe operating. means-for ,the automatic. reversing. valve, hood. valve. 56iscar-- ried-byv a` valve actuator or kicker llwliich is pivotally. mountedonv a trunn'ion 82,.and which isprovided y-withfan .upwardly Vdirected -arm .91.

The lower portion! of. kicker. 80 is enlarged, and

ceives, and-is jsornevvhanlonger than .the reartoiapivoted spring carrierr94.' Spring-carrier. 84

is pivotallysupported, by. 'means' of a pin; 38.and is provided with spaced Yarms |00 which arerdisof :the corresponding carrier arm to engage and positively move `the upper end 9| of the kicker '80,v intiatingvaV snap-over movement of the latter. .During the course of this snap-over movement, the end of slot 84 engages valve 58 and snapsit to its opposite'position.V During rightward pistonwmovement,..a reverse action. taires place, resulting. snappingthe valve 58 to the operating positionshown in .Figure 2. Both right-handl and. left-hand valve'. actions occur at, and, establish, normal limits ofthe pistonmovement.. ...T-he .motor isA shown in-Figure 2 at a stop'.-

ping. position, in. which. the right-hand piston- ,I Iiv is .immediately .adj acent its corresponding cylin-f' der closure I4, which positionis beyond .thelnorfmal right-hand limiter travel of theY m .|tor`,asv

established by .theautomatic.y reversingv valve mechanism. Such.. over .travel is` caused, -as describedb,elow,. by .action /of the. manual control valve. Ill 0`,:and is. accommodatedby .the automatic reversingvalvasince during theover travel, the spring carrier94lis-simply .pivot'ed by the correspondingabutmentl. I02,..to..a point. beyond the pointat whichthe snap. actionof kicker 80.' takes place.

The control valvel H0 is illustrated herein as beingof the. rotatabletype, rhaving a manually controlledloperating handle H2'. Valve .I I0 is received in a Ipocket ||.4`.provided therefor in the outerface ofthe. valve -block..5|, and .is retained on its. seat 66 by a spring -I |6,.which is-heldV in place. by .the removable cover plate. I I8.- Valve ||0Ecomprises a hood-like valve element |20,

having av projecting. portionV |22, which denes.

aY pairof -arcuately `spaced blind. pockets I 24 and |26; and is also carried with circumferentially projecting ange portions |20. The projection |22 is received ina slot. providedthereforin the body of the control valve. H0, vValve ||0 is .provided with an axially projecting cylindrical portion.|.30,. which is rotatably. journaledfin an axial bore. v|3`2 .provided therefor inthe Valve block l5 I. By manipulating the handle I2, valve ||0 is movable. between. the. parkingV position shown in Figurel, and in. the, lower-` two. .views of Figure 7; and the runningpositionshown in the upper two views of Figure; E v

The previously identied `control valve ports 64, 10, "16,-and 89 arearcuately arranged, as in the case of the reversing-.valve ports,and in addition, vthe control valve seat 66 is provided witha blindpocket |34.. l Y .-7

In the runningpositions,` control valve-pocket |26 bridges-and. interconnects passages 68 and `|5; pocket-|24 bridges andv interconnects pastion on the other hand; pocket |26Y bridges andV interconnects''passages` I5 land. 87;" and pocket |14 -ibridges `and#interconnects' passage 62- and' the pocket |34. It is noted that pocket |34 extends laterally beyond the flange |28 of the control valve element, so that the outer end portion is continuously exposed to atmosphere. In the justmentioned parking position, accordingly, pocket |24 vents passage 62 to atmosphere. Finally; in the parking position, the flange |28 closes 0E the remaining valve block passage 68.

It is believed that the operation of the present motor may best be understood with particular reference to the diagrammatic views of Figure 7.

As previously mentioned, the motor normally parks at its right-hand limit of travel as viewed in Figure 2, which corresponds to its left-hand limit of travel as viewed in Figures 1 and 7. Under such conditions, the automatic reversing valve is in a position in which it tends to establish circuits which cause the piston assembly to move to the right as viewed in Figure 7, which is the position of the reversing valve in the second view of Figure 7. Accordingly, if the manual valve |ll is moved from parking position to running position, the fluid circuits shown in the second view of Figure 7 are immediately established. In this figure, the right-hand piston chamber i9 is connected to the suction line 9, through a circuit which extends through passage B5, a portion of passage 62, control valve pocket |24, passage 81, reversing valve pocket 99 and passage 12 to the suction line di?. Under the same conditions, the left-hand chamber i1 is connected to atmosphere through passage 19, a portion of passage 15, control valve pocket |29, and passage 98, port 56 whereof is exposed to atmosphere. When the right-hand limit of travel is reached, valve 58 reverses its position, as pre -viously described, establishing the iiuid circuits shown in the top view of Figure 7, in which it is believed to be obvious that chamber i9 is connected to atmosphere through the now expose-d port 56 associated with passage 58; and chamber I1 is connected to the suction line 0 through a circuit which includes valve pocket G9, a portion of passage 15, and passage 19 into chamber I1.

So long, therefore, as the control valve H9 occupies the running position, motor 9 is caused to reciprocate between its normal left-hand and right-hand positions.

To effect a parking of the motor, valve i i9 may be moved to the parking position, shown in the lower two views of Figure 7, at any time, regardless of the direction of travel of the motor. If the control valve li)-v is moved to parking position, while the motor is traveling toward the parked position (third view, Figure 7), no change in the motor movement is eiected. In fact, the only circuit change which is produced by this movement of the control valve is that an additional atmospheric connection for chamber I9 is provided through the now bridged passage y92 and venting pocket i3d. When the motor reaches its normal left-hand limit of travel, reversing valve 59 makes it normal throw-over movement, establishing the circuits shown in the bottom view of Figure '7. In this view, chamber |1 remains connected to suction through a circuit which eX- tends from the suction line 40, passage 12, pocket $0, passage 81, pocket |29, a portion of passage 15, and passage 19 into chamber |1. At the same time, chamber I9 remains connected to atmosphere through a circuit which extends through passage 85, a portion of passage 62, pocket |26, and venting pocket |34 to atmosphere. The throw-over action of the reversing valve at the left-hand limit is thus ineffective to reverse the application of pressure to the motor, and the latter continues towards its left-hand or parking position. When such position is reached, the left-hand piston I5 seats against and closes off the passage 91 which, as previously described, interconnects passage 19 with the left-hand piston chamber i1. This engagement'holds the piston assembly in the parking position with a suction effect, and also resiliently brings the motor to rest.

If, on the other hand, the parking valve H9 is moved to parking position While the motor is moving away from its parking position, such movement interrupts the fluid circuits shown in the second View of Figure 7, and immediately reestablishes the connections shown in the bottom view of Figure 7. This action, of course, causes the motor to immediately stop and re-start in the opposite direction, toward the parking position. Under these conditions, no throw-over action of the reversing valve 58 takes place when the normal left-hand limit is again reached, for the reason that valve 53 is already in the position to which it would normally be moved upon arrival at the normal left-hand limit. Accordingly, no change in the supply and venting circuits for the motor takesl place at the normal left-hand limit and, as before, the motor continues to, and stops at, the left-hand terminal position.

Although only a single embodiment of the invention has been described in detail, it will be appreciated that various modicationsv in the form, number, and arrangement of the parts may be made without departing from the spirit and scope of the invention. yWhat is claimed is:

In a fluid motor, iirst and second members deiining iirst and second chamber spaces and movable relative to each other back and forth between normal limits under the influence of a reversibly applied vdifferential between higher and lower iiuid pressures, means dening a supply passage adapted for connection to a source of one of said pressures and at least a pair of passages corresponding respectively to said chamber spaces, valve mechanism for controlling said motor, said valve mechanism including reversing valve element having a single cavity and being operable for connecting said supply passage alternately to said chamber passages and being automatically operable at said limits to reverse said connection, and control valve means operable, at any time regardless of the position of said reversing valve means to establish a connection, through said reversing valve cavity, of said supply passage to said motor which causes a said relative movement toward one of said limits.

EMIL E. SIVACEK.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS y 

